Molded range and proximity sensor with optical resin lens

ABSTRACT

A method for forming a molded proximity sensor with an optical resin lens and the structure formed thereby. A light sensor chip is placed on a substrate, such as a printed circuit board, and a diode, such as a laser diode, is positioned on top of the light sensor chip and electrically connected to a bonding pad on the light sensor chip. Transparent, optical resin in liquid form is applied as a drop over the light sensor array on the light sensor chip as well as over the light-emitting diode. After the optical resin is cured, a molding compound is applied to an entire assembly, after which the assembly is polished to expose the lenses and have a top surface flush with the top surface of the molding compound.

BACKGROUND Technical Field

This invention is in the field of proximity sensors and, in particular,a laser diode proximity sensor in a single integrated package.

Description of the Related Art

Proximity sensors are frequently used in cell phones, tablets, andpersonal computing devices. For example, when a person is making a phonecall, a proximity sensor in the phone will detect when the phone isclose to the ear or hair during a call to switch off the screen fortouch sensitivity. Further, if the phone is placed face down on asurface, it will switch to screen off for power saving. The sensor mayalso include a ranging sensor to measure the distance to the object. Inaddition, the light sensor may include an ambient light sensor which isadded to the proximity sensor or ranging sensor. The ambient lightsensor in a smart phone will check the light in the immediate vicinityand vary the screen brightness to automatically adjust the screen basedon the ambient light.

FIGS. 1A and 1B are images of a prior art proximity sensor 10. Lookingat both figures together, the proximity sensor 10 of the prior artincludes a plastic housing 12 which is glued with an adhesive 14 to abase substrate 16. Apertures 18 and 20 permit light to be emitted andreceived, respectively. The diode 22 emits light which will be sensed bythe light sensor 24 if the proximity sensor is near an object, such asless than one to two centimeters away.

A glass lens 26 is attached by glue to the plastic cap 12 to protect thediode 22 and permit light to be emitted. Similarly, a glass lens 28 isglued to the plastic cap 12 adjacent the light sensor to protect andseal the cavity holding the chip and filter the light. The plastic cap12 also includes a central barrier 30 which is adhered by glue to thechip 24 in order to block light passing directly from the diode 22 tothe light sensor 28.

There are a number of shortcomings and difficulties with assembling thepackage of the prior art. A first difficulty is the number of smallparts which must be assembled. The package has a footprint area in therange of 2.5 to 2.8 millimeters and therefore the individual componentsare very small. The automatic machinery that assembles the device hasdifficulty working with such small parts. There is also significantdifficulty in lens placement accuracy. The lenses may tilt slightly,thus reflecting a large amount of light. The prior art has thedisadvantage of a large chamber and light which may be reflected fromthe glass lens. Another problem is the glue dispensing process maycreate voids, bubbles, or bumps, which make the different parts uneven,including the plastic cap, the diode, the central barrier 30, and thelenses. Another problem is the likelihood of glue overflow. If too muchglue is used, it may flow from underneath the central barrier 30 tocover part of the light sensing circuit 28. Accordingly, it is preferredto provide an improved proximity sensor.

BRIEF SUMMARY

According to principles of the embodiment as disclosed herein, anoptical resin is dispensed as a small drop which will harden to providethe lens over the diode and the light sensing array. The optical resinis transparent or may have a slight color to it in order to providecolor filter, if desired. The use of a liquid dispensed optical resinprovides a more reliable optical path than the prior art cap conceptwith the glass lens because the light is entrained within the opticalresin more completely.

After the optical resin is dispensed onto the light-emitting diode andthe light sensor, the chips, together with the optical lenses, areencapsulated in a molding compound that completely encases both of thechips as well as the optical pass. The molding compound provides theassurance of a complete block of all light that may cross-talk betweenthe light source and the light sensor. Accordingly, an additionalcentral barrier of a plastic cap is not needed to prevent opticalcross-talk. This permits elimination of the cap, which avoids the needto attach items together within a small tolerance. Further, thiseliminates the need for any glue at the central barrier, which avoidsthe problems of glue void, glue overflow, and the difficulty ofcarefully aligning the small parts.

Further, there is no need for the placement of the individual parts ofplastic and glass. Rather, the optical resin can be easily dispensedusing known technology, after which the entire assembly is encased inmolding compound. After the assembly is encased in molding compound, thearray is polished to expose the lenses and then cut into individualpackage die to provide the completed proximity sensor and module.

Among the advantages of the invented proximity sensor module is that itis lower in cost, along with being more rugged and reliable than theprior art. Further, the manufacturing steps are significantly simplifiedand there are higher yields of proximity sensor modules than waspossible in the prior art.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1A is a top plan view of a prior art proximity sensor module.

FIG. 1B is a cross-sectional view taken along lines 1B-1B of FIG. 1A.

FIG. 2 is an isometric view of a proximity sensor module at an earlyproductive stage according to one embodiment as discussed herein.

FIG. 3 is an isometric view of the proximity sensor module at a laterstage during manufacture according to principles as disclosed herein.

FIG. 4 is a cross-sectional view of one embodiment of the proximitysensor module of FIG. 2 at a final stage in manufacture.

FIG. 5 is an isometric view of an alternative embodiment of a completedproximity sensor module according to the principles as taught herein.

FIG. 6 is a cross-sectional view of an alternative embodiment of aproximity sensor module as taught herein.

FIGS. 7A-7J show the manufacturing steps of the proximity sensor module.

FIG. 8 is a flowchart showing different steps in the method ofmanufacturing the inventive proximity sensor assembly as disclosedherein.

FIG. 9 is a top plan view of an alternative embodiment of the proximitysensor model.

FIG. 10 is an isometric view of the lenses for use in the alternativeembodiment.

FIG. 11 is a cross-sectional view of the package of FIG. 9.

FIG. 12 is an alternative embodiment of the package of FIG. 9 having ablocking member overlying the substrate at a position between the lightand the sensor.

FIGS. 13A and 13B are views of an alternative embodiment having the LEDmounted on a separate lead.

FIG. 14 illustrates an optical overmold layer overlying bonding wiresand the light emitting diode of the embodiment of FIGS. 13A and 13B.

FIGS. 15A-15H illustrate a sequence of steps that may be followed in theformation of the device as shown in FIGS. 9-11.

FIG. 16 is a flowchart illustrating some of the steps carried out informing the device of FIGS. 9-11.

FIG. 17 is an isometric view of a mobile sensor stick having a pluralityof sensors thereon.

FIG. 18A is a side cross-sectional view of one embodiment of the mobilesensor stick of FIG. 17.

FIG. 18B is a schematic topside view illustrating the types of sensorsand their respective locations on the mobile sensor stick of FIG. 17.

FIG. 19 is a further alternative embodiment of the mobile sensor stick.

FIGS. 20A-20D illustrate various stages in the manufacture of the mobilesensor stick of FIG. 17.

FIG. 21 is a flowchart illustrating a series of steps carried out in theconstruction of the mobile sensor stick of FIG. 17.

DETAILED DESCRIPTION

FIG. 2 shows the inventive proximity sensor module 50 at an early stageof manufacture. The proximity sensor module 50 includes a substrate 52on which is mounted a light sensor chip 54. The light sensor chip 54includes at least one light sensor 56 and, in some instances, a secondlight sensor 58. The light sensor 56 is preferably a photon avalanchediode or diodes and thus can sense the presence as well as the quantityof light that impinges thereon. Mounted directly on top of the lightsensor chip 54 at a location spaced from the light sensor 56 is a lightsource 60. The light source 60 is preferably a laser diode, such as aDCSEL or other acceptable light emitter.

FIG. 3 illustrates the proximity sensor module at a next stage inmanufacture. A drop of optical resin is placed directly over each of thelight-emitting sources as well as over each of the light sensors. Anyacceptable transparent or translucent optical resin may be used. As willbe appreciated, the optical resin has a relatively high viscosity andthus will form a rounded ball or lump directly over the light source andlight sensor in which it is placed. A first drop of optical resin glue64 is placed over the light sensor 56, a second drop 66 is placed overthe light-emitting diode 60 and, if a further light sensor 58 ispresent, a third drop 68 is placed over any further light sensors.

The optical resin glue will be of a type that beads up to form a roundedbump or bubble because of the viscosity of the fluid when it is applied.It is then cured to harden, either with a UV cure, or heat, or otheracceptable cure.

As shown in FIG. 4, after it is cured, the assembly is encapsulated witha molding compound 70 that completely encloses the entire upperassembly, including the light sensor chip 54, the light-emitting diode66, as well as the lenses 64, 66, and 68. A baffle 72 is attached to thetop of the molding compound 70 in order to provide some protection tothe overall assembly, although this is not required. Preferably, thebaffle 72 has some electrical grounding in order to provide some ESDprotection for the proximity sensor module 50. If the proximity sensormodule 50 is sufficiently electrically isolated from other components,it may be possible to complete the assembly with just the moldingcompound 70 alone, and without the use of the baffle or other cover.Alternatively, in some embodiments, a metal cap or metal plate overliesthe proximity sensor module 50 as the uppermost layer. The metal capprovides the advantage of good electrical isolation as well as furthermechanical support and strength to protect the module as a whole.

FIG. 4 shows a cross-sectional view of the completed proximity sensormodule 50. The molding compound 70 fully encases the lenses 64 and 66 aswell as the sensor chip 54 and the diode 60.

The completed proximity sensor module 50 includes a baffle 72 overlyingthe lens assembly in order to provide apertures of the desired openingthrough each of the lenses 64 and 66. The baffle is attached by someacceptable adhesive, as can be seen in FIG. 4. Electrical contacts 55provide electrical connection from the light sensor chip 54 to externalcircuits. The substrate 52 is preferably a printed circuit board whichcontains a number of insulating layers and traces, as is well known inthe art. Electrical contact pads from chip 54 will be electricallyconnected to contacts in the upper portion of substrate 52, which arethen electrically connected to the contact pads 55 at the bottom of thesubstrate 52. The construction and connection of the printed circuitboard 52 to the sensor chip 54 is well known in the art, and thereforethe details of the internal electrical traces and the connection of thewires to the contact pads inside the substrate 52 are not shown;however, it will be appreciated that it is a standard printed circuitboard of the type which is well known in the art.

FIG. 5 shows a further alternative embodiment of the proximity sensor50, according to principles as disclosed herein. In this alternativeembodiment, no additional baffle plate 72 is provided. Rather, theuppermost layer of the proximity sensor module 50 is the moldingcompound 70 which formed the encapsulation layer. The top surface of thelenses 64 and 66 are flush with the top surface of the molding compound70 because of the final polishing stage, as discussed later herein. Inthis embodiment, the lenses 64 and 66 will not be exposed to the outsideenvironment, and therefore there is little to no likelihood that the topsurfaces would be subject to scratching or wear and tear from theenvironment. Rather, the proximity sensor module is inside of a cellphone, below an uppermost transparent display layer, and therefore thereis no need to have an additional baffle 72 provided. Accordingly, insome embodiments, the baffle 72 is preferred to provide openings of adesired shape and size, and to ensure the block from adjacent portionsof the display of the cell phone do not interfere with the properoperation of the proximity sensor. However, in other embodiments, themolding compound 70 is the outermost layer on both the top and sides, asshown in FIG. 5.

FIG. 6 shows an alternative embodiment in which an additional glass lens74 is provided over the molding compound 70. In those embodiments inwhich a glass lens 74 is provided, a small cut is made into the moldingcompound 70 between the light-emitting diode 60 and the light sensor 56,and is filled with the black glue or the opaque adhesive onto which theglass lens 74 is attached, to ensure that all light and cross-talk isblocked that might pass from the light-emitting diode 60 through theglass lens 74 and to the light sensor 56 within the package. Namely, acomplete block is made so that only light which leaves the package andbounces off another object can enter the light sensor 56.

The use of the glass 74 is advantageous if a particular color is to befiltered for. For example, if red, green, or blue glass filters are tobe used, the glass plate 74 can be the appropriate color filter whichprovides advantages in some range sensing devices.

FIGS. 7A-7J show the process for the assembly of the proximity sensormodule 50 as will now be described.

A starting substrate 52 is provided. The substrate 52 can be a printedcircuit board, or any other substrate in which alternating layers ofinsulator and electrically conductive trace lines can be provided.Various contact pads 80 together with the appropriate insulators 82therebetween are provided overlying the substrate 52 in order to providethe desired electrical connection to the light sensor chip 54.

The starting substrate 52 is a large substrate that can support an arrayof proximity sensor modules 50. Thus, many thousands can be assembledsimultaneously in a common process sequence and then the packages aresingulated, which provides significant advantages over the assemblytechniques of the prior art.

As shown in FIG. 7B, the light sensor chip 54 is attached to thesubstrate 52 with the appropriate contact pads 80 and insulating layers82. As shown in FIG. 7C, the light-emitting diode 60 is placed directlyon top of the light sensing chip 54. It is placed at a location whichwill not interfere with the light sensor array, and is sufficientlyspaced therefrom that when the molding compound encapsulates the chipand diode, it will be assured that there is a blockage completelybetween them to prevent cross-talk. The light sensor chip 54 containsadditional circuitry besides just the light sensing circuitry. Forexample, it may include a CPU and other logic circuitry which controlsthe light which is output from the photodiode 60, the light which isreceived by the light sensor 56, and coordinates the electrical signalsto each in order to calculate whether or not another object is proximateto the proximity sensor 50. Such additional electrical circuits in thelogic circuitry are well known in the art, and therefore are notdisclosed in detail. The diode 60 is placed over the portion of thelight sensor chip 54 which contains the logic circuitry. It thereforepermits the entire package to be made with a smaller footprint than ifthe diode 60 were side by side with the sensor array 54 and placeddirectly on the substrate 52. Further, the wiring layer 54 from thediode 60 goes to the chip 54 and does not go to the substrate 52. Thelight output from the diode 60 is controlled by the logic circuitry inthe light sensor chip 54, which also provides the power. Therefore anyconnection to the substrate 52 is avoided by the design as disclosedherein. There is a thick passivation layer over the light sensor chip 54that will mechanically and electrically isolate the circuits that areplaced thereon as appropriate. For example, a thick layer of siliconnitride, silicon carbide, or other passivation layer is applied over theentire light sensor chip 54. Then, an aperture to provide a contact padis etched in the passivation layer to provide electrical contact to thebottom of the LED 60 or, if a laser diode is used, to the VCSEL laserdiode 60. Thus, the bottom electrode of the diode 60 is directlyconnected to a contact pad on the top face of the light sensor chip 54by providing electrical connection through the passivation layer thatoverlies the light sensor chip 54. The diode is therefore placed on thelight sensor chip 54 at the appropriate location to be electricallyconnected at its bottom contact pad to the appropriate contact pad ofthe light sensing chip 54. The top electrode is connected by wire 84 tothe appropriate contact pad of the light sensor chip 54 to provideproper operation of the diode 60.

As shown in FIG. 7D, the light-emitting diode is electrically coupledwith bonding wires 84 to the light sensor chip 54. Further, the lightsensor chip 54 is electrically connected with bonding wires 84 to theappropriate locations in the support substrate 52.

As shown in FIG. 7E, after the light-emitting diode 60 and the lightsensor chip are electrically and mechanically connected in place on thesubstrate 52, a small drop of liquid optical resin is placed over eachof these optical components. In particular, a small drop 66 of opticalresin is placed over the light-emitting diode 60 and a small drop 64 ofoptical resin in liquid form is placed over the light sensor 56. Thedispensing of one drop of optical resin is easily accomplished usingpresent equipment which is able to deposit a single drop at a preciselocation. Current glue dispensing machines can be used for the placementof the single drop of optical resin. After the optical resin has beenplaced over all of the optical components on the proximity sensormodule, it is cured as appropriate either by heat, UV light, or otherappropriate cure technique depending on the type of optical resin whichis used. The shape as shown for the resin drops 64 and 66 may varyslightly depending on the type of resin and its placement with theoptical glue dispensing machine. For example, if it has a low viscosity,the liquid drops of the optical resin 64 may, when initially dispensed,be more rounded and in the shape of a drop of water that is beaded up onan oil surface. Alternatively, if a fairly stiff glue is used, which,while still liquid, has a high viscosity, the glue as dispensed from themachine may have a conical shape similar to that shown in 64 and 66.Accordingly, the exact shape of the optical resin as dispensed as aliquid is not critical, but will generally have a conical or roundedshape which completely covers the optical component. In a later stage,the topmost layer of the optical resin 64 and 66 will be polished andbuffed, in order to provide a clean light transmission surface.

As shown in FIG. 7F, the entire assembly is then placed in a mold andfully encapsulated with a molding compound 70. The molding compound isapplied as a liquid and flows completely around the entire proximitysensor assembly that is above the substrate 52. It seals the lightsensor chip 54 to the substrate 52, blocking all light which can reachthe light sensor directly from the diode 60 unless it goes outside tothe package. The molding compound 70 is applied to a sufficient heightthat it completely covers the drops of optical resin after they havecured. Sufficient molding compound 70 is provided to ensure that theoptical resin glue is always completely covered and then there isadditional height above it. As can be seen in FIG. 7F, the moldingcompound 70 may extend 10% or 20% higher than the lenses 66 and 64 toensure that they are completely covered.

As shown in FIG. 7G, the next step is a polishing of the entire assemblyas a single unit. Specifically, the top surface of the proximity sensormodule array is ground or polished back to remove the top portion of themolding compound. The removal of the molding compound continues untilsome portion of the optical resin is exposed, and then the polishing andgrinding continues until it is assured that a good portion of theoptical resin is exposed to the ambient to permit transmission andreception. The polishing is concluded with a fine buffing step whichleaves a high-quality optical surface at the uppermost layer of theoptical resin lenses 66 and 64.

The step of applying extra molding compound 70 that is ensured to besufficient to go above the top of the lenses 66 and 64, and thengrinding and/or polishing back the entire assembly provides theadvantage that the entire assembly can be encapsulated in a singlemolding step. Further, the molding compound is assured of completelyblocking all light that may travel between the diode 66 and the lightsensor 64 within the assembly itself, thus preventing all possiblecross-talk. The molding compound 70 is selected to be highly opaque andthus no light can pass through it. Rather, the only way that light canbe sensed by the light sensor 56 is if it comes from an outside source.The laser diode 60 must therefore emit light outside of the package andhave it be reflected back to be sensed by the sensor 56.

As shown in FIG. 7H, an appropriate protective cover, such as a baffle72 made of silicon carbide, a metal cap, or the like is applied to thearray.

As shown in FIG. 7I, the individual proximity sensor modules are thendiced by sawing them between each other to result in individualproximity sensor modules 50.

FIG. 7J shows the fully assembled completed individual proximity sensormodules 50 having a molding compound 70 with optical resin glue lenses64 and 66, as well as the appropriate baffle covering 72, all mounted ona substrate 52.

FIG. 8 shows a flowchart for carrying out the process of manufacturingthe proximity sensor module 50. At a first step, a large substrate 52 isprovided which has locations for an array of proximity sensor modules 50to be formed. The appropriate contact pads 80 and insulating layers 82are then applied to the substrate 52 so that it may receive the lightsensor chip 54. In step 102, a plurality of light sensor chips 54 areplaced on the substrate 52 aligned with the contact pads 80 which havebeen previously placed thereon. In step 104, a laser diode, such as aVCSEL laser emitting diode, or other appropriate light source, isattached directly on top of the light sensor 54. In step 106, the entireassembly has wire bonds or other appropriate electrical connectionsprovided.

After the electrical connections are provided, in step 108 an opticalresin drop is placed on each of the light-sensitive components,including the light-emitting diode 60, as well as the light sensors 56,as well as any other light sensors, such as ambient light sensor 58 orother light sensors on the chip 54. The optical resin is then cured,resulting in the optical lenses 64 and 66, as shown in FIG. 7E.

At step 110, the entire assembly is placed into a mold cavity, andmolding compound flows over the array, completely encapsulating theentire array and extending some height above the lenses 64 and 66.

As shown in step 112, the molding compound is cured with the appropriatecuring, whether by heat, exposure to air, UV, or the light. In step 114,the entire upper layer of the assembly is polished or ground in order toexpose the lenses 64 and 66. In particular, a blanket polishing takesplace over the entire assembly array to uniformly remove the moldingcompound 70 as well as to expose or remove portions of the optical resinglue 64 and 66. The polishing continues until a relatively large area ofthe optical resin is exposed. The optical resin is therefore assured ofhaving a top surface that is flush with the top surface of the moldingcompound 70.

In step 116, the appropriate cover is provided, such as a baffle 72, ametal plate that provides grounding, or other appropriate cover in orderto provide mechanical as well as electrical isolation of the proximitysensor module 50. One acceptable baffle material is silicon carbide,which may be applied as a blanket layer across the entire array and thenetched at the appropriate locations to expose the lenses. This is alow-cost method of providing a cover layer. The upper portion of thesilicon carbide can be electrically conductive in order to prevent straycharges from causing damage to the proximity sensor module 50.

In step 118, the array is singulated by cutting with a saw blade inorder to obtain individual assemblies 50.

FIG. 7J shows the fully assembled and completed proximity sensor module50, which corresponds to that shown in FIG. 4. In particular, the lightsensor chip 54 is mounted on a substrate 52, and an encapsulation layer70 of molding compound completely encases all four sides, as well as thetop of the light sensor chips 54. Further, the molding compound fillsall the spaces between the light-emitting diode 66 and the light sensor64. The appropriate protection baffle 72 is then added, which has anaperture either provided in advanced or etched therein, so that lightmay exit from the light-emitting diode 60 and be received by the lightsensor array 56 in order to carry out the proximity sensing function.

In one embodiment, the optical resin glue may have a small amount ofcolor added therein while it is in liquid form. The color can providethe function of filtering certain types of light in order to performspecific functions in the light sensing.

FIGS. 9-11 provide an alternative embodiment for carrying out theconcepts as newly disclosed herein. In particular, FIGS. 9-11 illustratean embodiment of a proximity sensor 131 in which an open space and aglass lens have been added above the optical resin glue. As shown in thefirst embodiment of FIG. 3, the small drop of optical resin is placeddirectly over the light-emitting diode 60 and the light sensor 56. Then,differently from the embodiment of FIGS. 4-8, a mold cavity having astep shape over the LED 60 is used which forms the molding materialleaving a space for a glass member to be placed directly over theoptical resin. See FIG. 11.

FIG. 9 shows a top side view of a glass element 130 positioned directlyover the light-emitting diode 60 and a glass element 132 positioneddirectly over the light sensor 56. These glass elements 130 and 132 aremade of selected glass material to have high transmission of the type oflight to be emitted by the light emitting diode 60 and the type of lightto be received by the light sensor 56. Further, the bottom of the glasshas a pattern printed thereon to further define and focus thetransmitted beam so that it is properly transmitted in a desired patternand to limit the receiving field of view so as to reduce the ingress ofunwanted ambient light. Additionally, filters can be placed thereon inorder to filter ambient light but pass at nearly full luminosity thetype of light emitted by the LED 60.

In particular, the glass lenses 130 and 132 are overlaid on top of theoptical resin dots 64 and 66. The optical resin captures the light, andis a low-cost, rapid technique to ensure that the optical element, suchas the LED 60 and the light sensor 56, are properly protected; however,the optical resin may not have sufficient qualities to be the type oflens needed. Accordingly, by providing an additional glass lens, whichis customized to the exact shape and optical properties needed, thelight can be assured to be transmitted in the correct pattern out of theLED 60. The glass lens 32 can have the correct shape and pattern inorder to be assured of receiving the signal from the LED 60. Inaddition, this permits the light to be filtered through two sequentialfilters, first an optical resin filter that can be made of a selectivecolor to filter certain types of light, both as emitted by the LED 60and to be received by the light sensor 56, and also, using the lenses130 and 132, which can also have different types of light filters, suchas to filter ambient light, different colors of light, or differentshapes, as will now be explained.

FIG. 10 shows examples of the particular glass elements 130 and 132. Ascan be seen, the glass element 132 has printed thereon a pattern 134which has a large aperture that will define the emission location of thetransmit beam out of the light source 60. Further, the printed pattern134 can shape the beam to a desired shape so that with a simple printedpattern, such as a type made by a silkscreen printer, the beam is moreeffectively shaped for transmission to be received by the light sensor56. Preferably, the aperture 136 of the light emitting glass 130 isrelatively large in order to bring in a large amount of light to beemitted by the light source 60. The glass can be antireflective andtuned to pass infrared, laser, ultraviolet, or the type of glass,depending on the particular source used for the light emission 60.Similarly, glass 132, which is positioned over the light sensor 56,includes a pattern 138 on the bottom of which is an aperture of thedesired shape. This aperture 140 is somewhat small and is shaped tolimit the amount of light which is able to enter the light receivingfield of view. The shape selected for the pattern 138 and aperture 140reduces the amount of unwanted ambient light that can reach the sensor56. Further, in one embodiment, the type of glass selected for the lightsensor glass 132 is selected to substantially block standard ambientlight that may come from indoor lighting of the type in which a cellphone is normally used, such as fluorescent light, incandescent lightbulbs, and the like, and permit passage of the type of light that isemitted by the light source 60. Thus, if the light source 60 is emittinginfrared light, the glass will be tuned to pass infrared light withlittle attenuation while blocking the light of normal visiblefrequencies. The lensing surface will therefore define the field of viewof the received array 56 of the light sensor.

FIG. 11 shows a side cross-sectional view of the proximity sensor 131package having the glass lenses 130 and 132 over the optical resin. Ascan be seen in FIG. 11, the glass lenses 130 and 132 extend over theoptical resin 66 and 64, respectively. There is an air gap 142 and 144,respectively, between the optical resin and the lenses 130 and 132.

The air gap 142 and 144 between the optical resin and the glass lensesprovides an additional optical shaping property. The top of the opticalresin can be concave, convex, or flat. Similarly, the bottom of theglass lenses 130 and 132 can either be concave, convex, flat, or someother shape. The air gap 142 and 144 between these two optical lensespermits the shape of each to be made independent of the other withouthaving to redesign either of them for each custom use. For example, insome uses, the bottom of the lenses 130 and 132 may be concave, whilethey may be convex in others. By leaving an air gap 144 and 142, thepackage can be a universal package that can have many different lensshapes applied. Therefore it can be mass produced for many differentcustomers, and then the individual customer that provides the particularlens 130 and 132 can do so of any shape, size, and dimensions theydesire.

FIG. 12 shows that an additional member, a central glue stopper 150, hasbeen added in-between the LED 60 and the light sensor 56 for anotherembodiment of the proximity sensor 147. This central glue stopper 150directly overlays and is in contact with the uppermost surface of thesemiconductor substrate die 54. This central glue stopper is provided inorder to avoid damage to the sensor die surface. In particular, thesemiconductor die 54 has a number of integrated circuits, processors,optical analyzers, and other transistor-based logic circuits therein.The circuits to drive the LED 60 are located in the integrated circuit54, as well as the sensors and processors to analyze the signal returnedfrom the light sensor 56. In order to avoid damage to the sensor die 54,it is helpful to ensure that the mold cavity, which is going to be inplace to produce the molding compound 70 that will encase the entirepackage, does not touch the die surface. Accordingly, a small gap isprovided in the mold cavity to ensure that the mold tool does notimpact, and thus potentially damage, the die 54 when the mold is closed.However, if there is a small gap, there is some risk that the moldingcompound will leak outside the edges of the die, and also a completeblocking member may not be formed. Accordingly, as an option to preventthe crosstalk of lenses 1 and 2 through an optical path, black glue maybe dispensed as a stopper layer to avoid having crosstalk of the lightbeam. The central stopper black glue height is selected to besufficiently high to prevent the mold cavity from contacting thesemiconductor die 54. Its height is selected to be higher than asilicone skin that may be placed over the semiconductor 54.

FIGS. 13A and 13B show another alternative embodiment of a singlepackage having a light emitter 60 and one or more light sensors 56. Theparticular embodiment of FIGS. 13A and 13B has a light emitter, such asan LED 60 a positioned on its own conductive lead 156. In particular,the inventive package 153 contains a laminated insulated carriersubstrate 154 having a plurality of leads wrapped therearound. The leadsinclude conductive leads 160, a lead frame 158, and an LED lead 156. Thelead frame 158 is a single metallic piece which is wrapped around thesides of the laminated substrate 154 and has a die pad 159 on which theintegrated circuit die 54 sits. The lead frame includes leads 157 ateither end of the lead frame, both of which wrap around the sides andbottom of the laminated substrate 154. In most embodiments, these willbe coupled to ground to provide a solid ground connection for the backplane of the integrated circuit die 54. A separate metal lead 156, whichis mechanically and electrically isolated from the lead frame 158, alsowraps around the same laminated substrate 154. A light source 60 a, suchas an LED, is mounted on the lead 156. It is the only element mounted onthis lead. Accordingly, the entire lead 156 can be placed at a desiredvoltage in order to properly drive the LED 60. As can be seen in FIGS.13A and 13B, lead wires 165 extend from the integrated circuit 54 to theLED 60 a to provide the electrical signals to drive the diode in thedesired sequence and intensity.

The integrated circuit die 54 contains two light sensors: a data lightsensor 56, and a reference light sensor 152. Their use and constructionwill now be explained. An optical resin 66 overlays the LED 60 a andencases the bonding wires 165. A first light sensor 152 is located onthe integrated circuit 54. The light sensor 152 is within the sameoptical resin as the LED 60 a, and therefore receives light each timethe LED 168 is illuminated. Further, the reference light sensor 152 ison the same semiconductor substrate 54 as the data light sensor 56.

The reference light sensor 152 and the data light sensor 56 operate asfollows. The reference light sensor 152 is able to sense ambient lightat all times and thus can register the result of all changes of ambientlight. In addition, each time the LED 60 a is illuminated, the referencelight sensor 152 receives the light. Accordingly, this provides areference signal that can be used to determine whether or not the datalight sensor 56 has received the same light. Both light sensors 156 and152 are on the same integrated circuit die and preferably have been madeidentical using the same process steps, and are of the same size withidentical operating parameters. Accordingly, the only difference in thesignal received from them will be whether or not they have each receivedany illumination from the LED 60 a.

The signal that is output by the reference sensor 152 can be compared tothe signal output by the data sensor 56. If the LED 60 is off, then bothsensors should have the same output. The reference sensor 152 cantherefore be used as a calibration sensor, and the output from acomparison between them can be set to zero when the conditions receivedat both are identical. Then, when the sensor is in use, the LED 60 a isilluminated. If there is not a reflective object adjacent to theproximity sensor 153, then the LED 60 will illuminate the referencelight source 152, but little or none of the light will be received bythe data light sensor 56. On those instances in which there is an objectclosely adjacent to the proximity sensor 153, then the light which isemitted by the LED 60 a will hit the adjacent object and be reflectedback towards the die 54 and will be received by the data light sensor56. In this instance, the type of light received by the data lightsensor 56 will be similar to the type of light received by the referencelight sensor 152. Even though the amplitude and intensity of the lightwill be somewhat different at the data light sensor 56 than at thereference sensor 152, it will still contain the same wavelength of lightand, in the event it is a laser-type diode, have similar opticalproperties to the light which is being sensed at the reference lightsensor 152. Accordingly, the circuit can determine that the lightreceived at the data sensor 56 has been output by the LED 60 a and notby some other source. It can therefore be a more reliable proximitysensor. Further, it will be much more accurate for positive results andavoid false negatives.

The particular structure of the proximity sensor 153 is advantageousbecause flat leads extend around the outer edges as well as the bottomof the package, as can be seen by the shape and construction of leads156, 157, 158, and 160. Thus, electrical connection can be made to theproximity sensor package 153 by connecting to either the sides or thebottom of the respective leads, as appropriate for the particular designin which the product is used.

FIG. 14 illustrates yet another embodiment of a proximity sensor 169. Inthis particular embodiment, a flat laminated substrate 166 is providedhaving a plurality of metallic leads 168 across the bottom thereof. Thisparticular package 169 does not have any leads that wrap around the topor the edges; rather, all electrical connection is through varioustraces and conductive lines within the laminated substrate 166 to thebottom contact leads 168. This proximity sensor module 169 has thelaminated substrate as a base on which one or more integrated circuits54 are positioned. In this embodiment, a light source 60 b is positionedon a conductive strip extending at a top region of the substrate 166.This strip can be an exposed copper contact plate which has beenprovided using well-known techniques for exposing copper contact platesas used in printed circuit boards, or other technique. A single largeovermold completely encases one end of the integrated circuit die 54,which includes the bonding wires. In particular, the optical overmold164 extends off one or both sides of the semiconductor die 54 in orderto encapsulate the wire bonds. The wire bonds are not shown because theyare within the encapsulated section 164. The semiconductor die 54 hasall of the wire bonds located just at one end, and internal routing ofthe conductive wires is made in various layers in order to ensure thatno wire bonds need to be at the end that includes the data light sensor56. The data light sensor 56 includes an optical resin 64 which enclosesit and overlays the portion of the semiconductor die 54.

FIGS. 15A-15H illustrate a sequence of steps in the manufacture of theproximity sensor 131, as shown in FIGS. 9-11. Slight variations can bemade to these steps as discussed here in order to make the embodimentsof FIGS. 12, 13A, 13B, and 14, as will be explained at various stagesherein. FIGS. 15A-15H will be described in combination with the methodsteps shown in FIG. 16 for ease of understanding.

Referring jointly to FIGS. 15A-15H and 16, a first step in themanufacture of the proximity sensor 131 is to begin with a bare leadframe in step 200. In a different processing sequence, in a differentlocation, a semiconductor die 54 is constructed. This begins with thestep of wafer lamination 300, as shown in FIG. 16, the wafermanufacture, which includes a back grind and polish as shown in step302, and then the mounting of the wafer on the appropriate substrate forsingulation. The wafer is singulated in step 306 in order to obtain theindividual die 54, as shown in FIG. 15A. The die 54 is thereaftermounted on a lead frame, and the combination is then mounted in step 202to a support substrate 170.

In a different location, the LED 60 is manufactured. This is generallycarried out with a reconstruction wafer of a plurality of LEDs in step203, as shown in FIG. 16. The LED 60 s are constructed using knowntechniques, diced and then attached to the top of the die 54 in step204, as shown in FIG. 16. The semiconductor die 54 and LED 60 are wirebonded to each other and to the lead frame in step 206. A black gluelayer 150 is then applied across the top of the semiconductor die 54, instep 207. The support substrate 170 holds three examples of theproximity sensor 131 at this stage of the construction, corresponding tostep 207 of FIG. 16.

While the black glue layer 150 is not required, it is preferred in thoseembodiments in which a mold cavity is used having a clamshell mold thatcloses thereover in a particular shape.

Subsequently, in step 208, a small amount of optical resin is placedoverlying the LED 60 and the light sensor 56. The optical resin 64covers the light sensor 56, while optical resin 66 covers the LED 60.Next, in step 210, as shown in FIG. 15C and 16, a mold is placed overthe assembly of proximity sensors 153. After the mold is placed over itan encapsulating compound, molding compound, or the appropriateencapsulant 140 is injected into the mold an cured to have the shape asshown in FIG. 15C. The mold has a shape to provide an open spacedirectly above the optical resins 64 and 66, and then a flange in theappropriate shape in order to support glass lenses 130 and 132. Inparticular, as shown in FIG. 15D and step 212, glass lenses 130 and 132are attached by the appropriate adhesive, which is then cured to rigidlyfix them directly to an exposed flange of the encapsulant 140. When theyare attached to the encapsulant 140, and open air space 142 and 144,respectively, is left over the LED and the light sensor optical resins.The lenses 130 and 132 seal on all edges so that no dust or debris cancollect in the spaces 142 and 144. In one embodiment, they are sealedwhile under vacuum to ensure that not dust or debris may enter thespace, while in other embodiments they are sealed while the process isin clean, ambient air, also assuring that no dust or dirt can interferewith the optical operation of the proximity sensor 131. Next, theassembly is mounted on a sawing carrier tape 172 in step 214. This isdone by inverting the substrate 170, which contains the plurality ofproximity sensors 131 and then supporting it on the sawing carrier tape172. The support substrate 70 is then removed by the appropriate means,whether grinding, chemical wet etch, polish, or the appropriate removaltechnique. This leaves the metal leads coupled to the semiconductor die54 exposed as the uppermost layer, as shown in FIG. 15F, and in step 216of FIG. 16. Next, the proximity sensors 131 are singulated by cuttingthrough the encapsulant 140 with a saw 174 at each of the proximitysensors. In particular, the saw 174 will cut an aperture 176 which iscompletely through the encapsulant molding compound 140, and partiallythrough the sawing carrier tape 172. The sawing carrier tape 172 stillremains sufficient mechanical strength to hold the assembly together,and all of the individual proximity sensors 131 are singulated. Afterthis, the sawing carrier tape 172 is removed by any appropriatetechnique, whether chemical etch, grinding, dissolving in water, peelingaway, or other appropriate technique. The proximity sensors 131 aretherefore singulated as shown in FIG. 15H and then tested for shipmentto the customers.

FIGS. 17-21 illustrate another embodiment of various sensors. As shownin FIG. 17, a sensor stick 400 is in the form of a small microstickhaving metal contact leads 402 at one end thereof and a form factorsimilar to that of a memory stick. In particular, the leads 402 are of aconfiguration compatible with most computers, such as a USB port, adigital card, a micro SD card, an SDHC card, or the like. The sensorstick 400 includes a plurality of sensors all mounted on a commonsubstrate and electrically connected to the contact pads 402 forinsertion into any computing device. The sensors on sensor stick 400include environmental sensors 404, ambient light sensors or projectors406, proximity sensors 408, motion sensors 410, as well as othercommunication sensors such as Bluetooth, Wi-Fi chips, and other wirelessconnectivity chips according to any acceptable protocol for wirelesscommunication. Each of these sensors are appropriately supported by theprinted board substrate 401, and enclosed with an encapsulant or moldingcompound 403. The details of the various sensors, as well as theirconstruction, and other operational details will now be disclosed andexplained relative to FIGS. 18A-21.

As shown in FIG. 18A, the sensor stick 400 includes a printed boardcircuit substrate 401 having a plurality of leads 402 positionedtherein, with conductive layers alternating with insulating layers, asis well known in the art of PCBs. At one end of the PCB 401, a pluralityof leads 402 are provided that electrically connect to one or more ofthe circuits on the substrate 401. While the contact pads 402 in thisparticular cross section are not shown as connecting to each of thesensors 404-410, it will be appreciated that such connections are madein the various layers and in planes other than that shown in the crosssection of FIG. 18A.

One type of sensor on the sensor stick 400 is an environmental sensor404. This environmental sensor 404 is distinguished by the requirementthat it be exposed to the ambient air in order to sense the environmentaround the sensor. In most instances, this will mean that the sensor isalso exposed to the ambient light and temperature, though in some typesof sensors, it is sufficient that the environmental sensor 404 beexposed to the ambient air and may have the appropriate cover thereonwith apertures therein so it is not exposed to light. It may also besomewhat temperature isolated or have its own heater so that itstemperature is different than that of the local temperature. However, inmost embodiments, the environmental sensor 404 will be exposed to theambient atmosphere. This ambient sensor 404 includes a semiconductor die412 having the appropriate ambient sensor 414 mounted thereon. Theambient sensors may include sensors capable of sensing for a particulargas, such as CO, CO₂, methane, or other gas for which sensing smallquantities of gas is particularly beneficial. In addition, theenvironmental sensor 404 may include, in addition to or instead of a gassensor, a UV light sensor, an infrared light sensor, a temperaturesensor, humidity sensors, air pressure sensors, and the like. While onlya single environmental sensor 404 is shown in the cross-sectional viewof FIG. 18A, the topside schematic view of FIG. 18B gives an example ofthe type of sensors which may be organized along the sensor stick 400.Namely, at one end thereof are the contacts 402, and electricallyconnected and stretching along the length of the substrate 401, are oneor more of the appropriate environmental sensors in the example of FIG.18B. The examples include methane, CO₂, CO, IR, UV, humidity,temperature, and pressure. The sensor stick 400 may have only one ofthese environmental sensors, or in one embodiment it may include allsuch environmental sensors on a single memory stick.

Next will be a light emitter and/or a light sensor 406. In oneembodiment, the light emitter 406 is a mini-projector which has aplurality of micro-mirrors therein and, once the sensor stick 400 isinserted into a computer, it receives power so that a small amount oflight in a mini-display may be projected out of the memory stick. Singlechips that are capable of providing the projection of a viewable imageare known, and such a micro-mirror chip may be mounted at location 406on this sensor stick 400, as shown in FIG. 18B. Alternatively, or inplace of the light emitter 406, one or more ambient light sensors 408and/or proximity sensors 408 may be provided. The sensors 408 may senseambient light and may also sense whether the sensor stick 400 is closelyadjacent to another object and therefore may include the proximitysensors 408, ranging sensors to measure the distance, and otherappropriate sensors therein within the same substrate and adjacent tothe other sensors. The proximity sensor 408, which may include a rangingsensor and ambient light sensor, may be constructed along the lines ofthe embodiment shown herein with respect to FIGS. 1-16, and thenconnected to this sensor stick using the appropriate connectingtechnology as is known in the art.

Also included on the sensor stick 400 are various motion sensors 410. Inone embodiment, the motion sensors 410 may include a magnetometer 410 a,a gyroscope 410 b, or an accelerometer 410 c. Other types of motionsensors may also be included. Adjacent to, either on the same die, ormounted on a similar interposer board, the wireless connectivitycircuits 411 may also be mounted, as shown in FIGS. 18A and 18B. Inparticular, at one end of the sensor stick 400 can be a plurality ofwireless connectivity circuits which may include Bluetooth, Wi-Fi, NFC,IR communication protocols, or other optical communication protocols. Inparticular, the sensor stick 400 can be connected by two differenttechniques to a user's local computing device. It can be connected as awired device with contact pads 402 in the appropriate patterns, such asfor a USB, SD card, or the like. It can receive power through thissource in order to power each of the sensors mounted on the sensor stick400. In addition, the power can also provide the drive power for anywireless connections, such as via Bluetooth, Wi-Fi, and the like asdescribed herein. Thus, it can communicate with the computer to which itis connected via the hardwire connections through contacts 402, while atthe same time coupling wirelessly to the same computer via a wirelessroute so the data may be provided by two independent techniques, oralternatively it can be connected wirelessly to another computing deviceand provide data to multiple computing devices. It can provide the samedata simultaneously to two or more different computing devices. It canprovide the data via the hardwire contacts 402 to the computing deviceto which it is plugged in the socket, while at the same time providingthe same identical data to one or more computing devices to which it isconnected wirelessly. Yet, it has no battery. So it uses the powerprovided to it by one computer to receive, analyze and organize data,then send it wirelessly to another computer.

The current embodiment has the benefit of providing a user-selectablearray of sensors which they may obtain and then connect to a computingdevice of their choice. For example, a user may desire to have one ormore environmental sensors that work easily and smoothly with their cellphone, an iPad, or other microcomputer. Rather than being forced to buya low-cost cell phone which contains all of these sensors, the user canbuy a sensor stick 400 having the particular sensor configuration whichthey desire. They can thereafter plug the sensor stick into thecomputing device, such as a cell phone, and automatically provide a widerange of additional sensing capability. In one preferred embodiment, thecomputing device is the user's cell phone. The user's cell phone, whichhas a large amount of computing power within the cell phone itself,together with the battery, can therefore be used to power, collect datafrom and interact with the various environmental sensors 404, projectone or more images using projector 406, as well as sense motion andperform other activities according to those which are provided on thesensor stick 400. The user can therefore buy a lower-cost cell phonewhich does not have any of these particular sensors, and then buy theparticular sensor stick which meets their needs, and thus, by insertingit into the USB slot of the cell phone, can turn the cell phone into ahigh-quality environmental sensor in a very short period of time. If theuser decided to use a lower-cost sensing stick 400, they can buy onethat has only one or two sensors on it, and can carefully those tomaximize the ones which they would use for the most economical costpackage. The sensor stick 400 is also fully portable to other devices.

FIG. 19 illustrates another alternative embodiment of the sensor stick400. In this embodiment, two environmental sensors are shown side byside, one for sensing methane and the other for sensing CO₂. Thus, ascan be seen, it is possible to have mounted side by side, eitherlinearly or in parallel, two or more environmental gas sensors on thesame substrate. These can be physically isolated from the encapsulationlayer 403, as shown in FIG. 19, having their own case 417, or,alternatively, can be within the same encapsulant 403 as shown in FIG.18A. The other components as shown in FIG. 19 correspond to those shownin FIG. 18A, and therefore will not be repeated, for ease of reference.

FIGS. 20A-20D illustrate a series of steps by which the sensor stick 400can be constructed. The sequence of steps shown in FIGS. 20A-20Dcorrespond to some of the steps in the flowchart of FIG. 21, andtherefore FIG. 21 will be referred to in parallel with FIGS. 20A-20D.

In a first step 430, as shown in FIG. 21, a bare printed circuit boardsubstrate is provided. In most embodiments, this is a laminatedsubstrate having alternating and conductive and insulating layers. Thiswill be in the form of a large array having a plurality of substrates,in most instances more than a hundred substrates for a hundred differentsensor sticks 400. They begin as a large matrix or array and a singleprinted circuit board, and then later will be singulated as explainedherein. In a subsequent step 432, the individual dies are attached tothe correct locations in the matrix for the sensor sticks 400. These areattached by pick and place machines and are soldered with theappropriate technique so as to be electrically connected on the backside to the exposed bonding pads of the substrate 401. After this, theassembly is subjected to the appropriate heating step 434 such as in aplasma or other appropriate adhering technique that provides electricalconnection between the individual semiconductor die and environmentalsensors to the sensor stick 400. While the use of plasma bonding isshown in step 434, any acceptable technique for electrically connectingthe various sensors to the respective dies to which they are connected,and then the connecting of the dies to the printed circuit board 401 areacceptable. After this, the various chips are wire bonded to the printedcircuit board as well, so that individual leads may be connected in thewire bond step 436. After this, the appropriate optical resin is appliedand then cured, the techniques of which have been previously describedwith respect to the other embodiments of the proximity sensor. Thisoptical resin may be used on the light emitters as well as on the lightprojector, or any other light transmitting or receiving die location. Atthis stage the appropriate cover tape is positioned over theenvironmental sensor 404 to ensure that during the application of thevarious chemicals, resins, and other etching, that the environmentalsensor 404 is not compromised or damaged. After all of the appropriatesensors and/or transmitters are mounted on the substrate 401 of thesensor stick 400, then the sensor stick is placed in a cavity of a moldand encapsulation material 403 is applied in order to encase the varioussubstrates and semiconductor chips. After the encapsulation material 403has been applied, the sensor stick is of the status shown in FIG. 20A.At this stage, step 442 of FIG. 21 is carried out by the appropriateetching, grinding, polishing, or otherwise removal of the upper portionof the encapsulation layer 403. This layer is removed until theappropriate portions of each sensor are ready for exposure. Namely, theremoval is carried out in an anisotropic fashion to expose the lighttransmitting and light receiving members, while at the same timeproviding an opening for access to the environmental sensors 404, asshown in FIG. 20B. After this, the appropriate baffle, lenses, in step444 as shown in FIG. 21, which can be seen as layers 426 and 428 in FIG.20C. In particular, the appropriate cover with the apertures, focusingmembers, and the like are added so as to provide a final package. Afterthis, in step 446, the matrix of packages that was present in FIG. 20Aand in step 430 is cut along what will be the boundaries of the sensorstick 400, so that the individual sensor sticks are prepared forsingulation. At this stage the final cover or the environmental sensor404 is removed, as can be seen by compared FIG. 20C to FIG. 20D. Thiscan be done by the appropriate etch, whether anisotropic ion etch,isotropic wet etch, selective laser ablation, or the like.

Final singulation is carried using well-known techniques, such as thosedescribed herein previously with respect to FIGS. 15E-15H and 16. Thismay include a sawing tape in step 448, and then final singulation isillustrated in step 450.

The various embodiments described above can be combined to providefurther embodiments. All of the U.S. patents, U.S. patent applicationpublications, U.S. patent applications, foreign patents, foreign patentapplications and non-patent publications referred to in thisspecification and/or listed in the Application Data Sheet areincorporated herein by reference, in their entirety. Aspects of theembodiments can be modified, if necessary to employ concepts of thevarious patents, applications and publications to provide yet furtherembodiments.

These and other changes can be made to the embodiments in light of theabove-detailed description. In general, in the following claims, theterms used should not be construed to limit the claims to the specificembodiments disclosed in the specification and the claims, but should beconstrued to include all possible embodiments along with the full scopeof equivalents to which such claims are entitled. Accordingly, theclaims are not limited by the disclosure.

1. A structure, comprising: a semiconductor die having a first surfaceand a second surface; a light sensor in the semiconductor die andbetween the first surface and the second surface; a light emittingdevice on the first surface of the semiconductor die; a glue stopperelement on the first surface and between the light emitting device andthe light sensor; a first resin lens that encapsulates the lightemitting device on the first surface; and a second resin lens thatencapsulates the light sensor on the first surface.
 2. The structure ofclaim 1, comprising a wire that couples the light emitting device to thesemiconductor die.
 3. The structure of claim 1 wherein the first resinlens abuts the light emitting device.
 4. The structure of claim 1,comprising a molding compound on the semiconductor die and surroundingthe first resin lens and the second resin lens.
 5. The structure ofclaim 4 wherein the molding compound includes a first opening alignedwith the light emitting device and a second opening aligned with thelight sensor; and wherein the first resin lens is in the first openingand the second resin lens is in the second opening.
 6. The structure ofclaim 5 wherein the first resin lens and the second resin lens are eachcoplanar with the molding compound.
 7. The structure of claim 4,comprising a baffle layer over the molding compound, the baffle layerpartially covering one or more of the first resin lens and the secondresin lens.
 8. The structure of claim 1, comprising a glass layer overone or more of the first resin lens and the second resin lens.
 9. Thestructure of claim 4, comprising a glass lens in the molding compoundand over the first resin lens.
 10. The structure of claim 9, comprisinga gap in the molding compound and between the glass lens and the firstresin lens.
 11. The structure of claim 10 wherein the gap includes air.12. A device, comprising: a substrate having a plurality of conductivecontact leads; an encapsulation layer over the substrate, the pluralityof conductive contact leads exposed from the encapsulation layer; and aplurality of structures in the encapsulation layer and coupled to one ormore conductive contact leads of the plurality of conductive contactleads, the plurality of structures including: a semiconductor dieincluding a light sensor in the semiconductor die; a light emittingdevice on a surface of the semiconductor die; and a glue stopper elementon the surface of the semiconductor die and between the light emittingdevice and the light sensor.
 13. The device of claim 12 wherein thesubstrate is a printed circuit board.
 14. The device of claim 12,wherein the plurality of structures include: a first resin lens thatencapsulates the light emitting device on the surface; and a secondresin lens that encapsulates the light sensor on the surface.
 15. Thedevice of claim 12, comprising a glass layer over the encapsulationlayer.
 16. A method, comprising: mounting a light emitting device on afirst surface of a semiconductor die, the semiconductor die having alight receiving sensor on the first surface laterally with respect tothe light emitting device; forming a glue stopper element on the firstsurface and between the light emitting device and the light receivingsensor; after the forming the glue stopper element, forming a firstoptical resin overlying the light emitting device; and after the formingthe glue stopper element, forming a second optical resin overlying thelight receiving sensor.
 17. The method of claim 16, comprising: forminga molding compound over the first surface of the semiconductor die andsurrounding the first optical resin and the second optical resin. 18.The method of claim 17, wherein the forming the molding compoundincludes: forming the molding compound over the first optical resin andthe second optical resin; and exposing the first optical resin and thesecond optical resin from the molding compound by planarizing themolding compound.
 19. The method of claim 16, comprising attaching asubstrate onto a second surface of the semiconductor die, the secondsurface opposite to the first surface.
 20. The method of claim 19,comprising forming a conductive contact structure on the substrate.